Above -- Garami and the Molecule. Left -- Start of
the record flight at Haley Field, where the Molecule outflow larger
ships. The monocoque fuselage and wing installation are points to
note. Nose detaches.

With the advent of improved tiny engines, Class A gas
models are coming into their own in aeromodeling. As with everything in
life, competition results in improved products for the ultimate benefit of
the consumers --that's us, the model builders.

Having used many engines, the writer has found much
satisfaction with the Atom, the smallest and lightest production engine.
The Molecule was designed specifically for this superlight engine, and
this accounts for the low total weight of twelve ounces.

At the official Eastern States Gas Model Championship
the ship proved itself by spectacular performance. By winning first place
and setting a sensational record, the ship lifted Class A modeling to a
new level and gave it the respectability and recognition on par with other
classes of powered model flying. It wrote finish to flights of a few
seconds that were predominant hitherto.

The influence of this method of sheet balsa monocoque
construction is being felt in all modeling circles. Several commercial
models have adopted this system, and the Molecule is the latest example
employing several new wrinkles.

While the engine used is responsible for a greater rate
of climb, the inherent characteristics of the Molecule make possible the
flat glide and soaring ability.

BODY

Make the lower half of the body first. Study the top
view and fuselage detail and assemble the two longerons with all the cross
braces. Although the plan does not show a cross brace at the very front,
cement one in to bring the total width up to 2-5/8". This will be removed
when the body is completed.

Cut out the two blanks, pin them together and sandpaper
to uniformity. Look over the two curves and see that there are no wavy or
uneven sections left in the outline. Shape two of each of all the formers
out of 1/8" sheet balsa.

Now lay the two blanks down so that the underslung
rudders "toe" together, and brush clear dope on the entire surface up to
the point where the rudders begin. Make sure that the dope covers evenly.
A second coat is applied after ten minutes.

From this time on the two blanks will slowly curl up.
The longer the drying period the more curve will be acquired. Experiments
showed that this gradual warping will go on for days and days if it is not
stopped. Our purpose is to get only a sufficient curve to fit the formers,
so when the curvature is slightly less than Former 1, glue and pin in this
part and follow up with 2 and 3.

Never dope a pair of blanks before you are about to
take part in a long game of checkers, unless you expect to see a balsa
pretzel when you get back to your model. In fact you should not stop
working until the whole lower half is completed.

Now take the two blanks and cement them to the side of
the longeron assembly. Use plenty of pins and do not forget that the
longeron is only halfway in (1/16"); the other half sticks out to
accommodate the top half of the body. Next pull the bottom seam together.
Although you may be able to do it with pins, we strongly recommend the use
of cellulose tape for a perfect job. About ten 3" -- long pieces will hold
the seam together. Cement on the inside of the body, except the
rudder part, which is cemented on the outside.

Use this same method in creating the top half of the
body. Naturally this seam is very hard to cement on the inside, so we will
do it on the outside. On any outside cementing be very careful not to
spill cement on the surface -- and use it sparingly so as not to spoil the
appearance of the body.

Build up the cabin roof out of 1/8" balsa. (Three
pieces -- the two sides and a front cross piece.) Cut out the tilted
former in front of the cabin, which is the same as two No. 1 formers in
one piece. Pin and cement this former at the same angle as shown. Notch in
the body top behind the cabin roof about 1/4" deep and cement the roof
into place. Now fasten the three cabin struts, paying special attention to
the line-up of the roof from every direction. The cabin blanks need only
one coat of dope, since the bulge at this point is very little.

The cabin windows are cut after the blanks have been
cemented into place. A small brace between windows will help to stiffen
this spot. Use heavy celluloid for the windows.

Smooth out the entire body with fine sandpaper Finish
by brushing one or two coats of microfilm solution on the surface first,
followed up with one coat of varnish. It is important to have some finish
on the body which will withstand the rotting effect of gas and oil. But
stay away from dope and paint, as they will put the body out of shape in
time. The microfilm solution and varnish are absolutely harmless in this
respect.

Make the nose the following way: Copy the two front
formers onto a piece of paper. Cut each piece 3/32" smaller all around.
Cut 1/2" off the curvy part of each in a straight line. These cut-offs
will be filled in with a solid block. Cut out the formers of 1/8" sheet
and leave them solid. Now cement the two together at the same angle as the
front of the body. While an auxiliary 1/4" x 1/4" holds the front former
in place, plank the sides with 3/16" soft balsa and put solid blocks on
top and bottom. Carve and sandpaper to shape. Use clear dope and paint
inside and out in order to make it gas-proof. Two bamboo tracks anchored
in the bottom of the nose support the coil. The battery box is made of
hard 1/16" sheet balsa and cemented firmly. The landing gear is of 1/16"
piano wire faired in and reinforced with a large-face brass bushing on
each side of the nose.

The motor is mounted on two aluminum brackets which in
turn are screwed to the front former. I have used a sawed-off Austin timer
-- but, shifted a little forward, even a fullsize one will fit in.

Solder all the connections into a firm joint. To avoid
losses through interference, the high-tension wire is brought through a
slot between the nose and the cabin front. The whole nose is held firmly
to the body by rubber bands on each side. Provide piano-wire hooks for
this purpose, both on the nose and body.

WING AND TAIL

The wing is made in two halves. Cut out all the ribs
for the straight part of the panel. Pin the trailing edge down and
butt-joint the two end ribs. Now slide the spar through the notches and
fasten the leading edge. Follow with the rest of the ribs. Bend the bamboo
tips above the gas range, and notch them in place. Fit in the smaller tip
ribs, which are sanded lower and lower toward the tip.

The front cut-out ring may look odd to some, but it is
the only way to preserve the cabin position.

The tail employs no spar. The outline is cut out to
shape and assembled. Flat balsa ribs are set in, whereupon the edges are
sandpapered into a streamlined section. The rudder tab is solid balsa
hinged with small aluminum pieces. Cover all the surfaces with single Jap
tissue. A couple of coats of dope should make it water and gas-proof to a
reasonable degree. The wing and tail units are fastened with rubber hands.

FLYING

Glide the model without the prop, whose weight is
replaced with a rag bundled around the motor. If there is any incidence
change necessary, do it on the elevator. When the hand glide is perfected,
leave the rudder in straight position, open the motor to about
seventy-five percent and hand-launch the model ten to twenty degrees off
the wind to the left. If it does not continue to turn in the same
direction and stalls around under power, give it one-eighth-inch left
rudder the next time. All adjustments should be carefully considered
before being put into effect.